AU628137B2

AU628137B2 - Pharmaceutical treatment

Info

Publication number: AU628137B2
Application number: AU50600/90A
Authority: AU
Inventors: Malcolm Richard Boyd; David Sutton
Original assignee: Beecham Group PLC
Current assignee: Novartis International Pharmaceutical Ltd
Priority date: 1989-03-03
Filing date: 1990-03-01
Publication date: 1992-09-10
Anticipated expiration: 2010-03-01
Also published as: CY1870A; EP0388049B1; ES2072386T3; DK0388049T3; HK116795A; GB8904855D0; JP2513519B2; IL93594A0; CA2011238C; IL93594A; HU901252D0; EP0388049A3; DE69019404T2; EP0388049A2; LV10923B; US6136813A; HU205715B; IE900733L; JPH02275821A; ZA901572B

Abstract

Pharmaceutical use of a compound of formula (A): <CHEM> or a pro-drug, or a pharmaceutically acceptable salt, phosphate ester and/or acyl derivative of either of the foregoing; in the treatment of hepatitis B virus infections.

Description

628137 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION NAME ADDRESS OF APPLICANT: 0

S*

Beecham Group p.l.c.

Beecham House Great West Road Brentford Middlesex TW8 9BD United Kingdom NAME(S) OF INVENTOR(S): Malcolm Richard BOYD David SUTTON ADDRESS FOR SERVICE: DAVIES COLLISON Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: Pharmaceutical treatment The following statement is a full description of this invention, including the best method of performing it known to me/us:- 01 la- B2692 02 03 04 This invention relates to a method of treatment of 06 viral infections caused by hepatitis B virus, in humans 07 and animals, and to the use of compounds in the 08 preparation of a medicament for use in the treatment of 09 such infections.

11 EP-A-141927 (Beecham Group discloses 12. penciclovir, the compound of formula 1 .01. o

N

19 NH2 1 2 19 (CH2)2 HO-CH -CH-CH -OH 21 2 2 22*** 2 5 (A) 24 2A' and salts, phosphate esters and acyl derivatives 26 thereof, as antiviral agents. The sodium salt hydrate 27 of penciclovir is disclosed in EP-A-216459 (Beecham Group 29 Pro-drugs of the compound of formula are of formula 31 01 2 B2692 02 03 x 04

N

<N

06 N 07 N N H (CH 2 2 08 12 09 HO-CH -CH-CH -OH 09 2 2

(B)

11 and salts and derivatives thereof as defined under 12 formula wherein X is C 1 -6 alkoxy, NH 2 or hydrogen. The compounds of formula wherein X is C016 alkoxy or NH 2 are disclosed in EP-A-141927 and the compound of formula wherein X is hydrogen, 1 :c disclosed in EP-A-182024 (Beecham Group A particularly preferred example of a compound of formula 4: is that wherein X is hydrogen and wherein the two 19 OH groups are in the form of the acetyl derivative, described in Example 2 of EP-A-182024, hereinafter 21 referred to as famciclovir.

The compounds of formulae and and salts and 24 derivatives thereof have been described as useful in the treatment of infections caused by herpesviruses, 26 such as herpes simplex type 1, herpes simplex type 2 27 and varicella zoster viruses.

29 It has now been discovered that these compounds have activity against the hepatitis B virus, and are 31 therefore of potential use in the treatment of 32 hepatitis B virus infections.

33 34 Accordingly, the present invention provides a method of treatment of hepatitis B virus infections in mammals, 36 including humans, which method comprises the 37 administration to the mammal in need of such treatment, 38 an effective amount of a compound of formula -3- 0

N

H

NN N NH 2 (CH2

(A)

HO-CH2CH-CH-CH2-OH or a pro-drug of the compound of formula of formula

X

N

N< N (CH 2 15 1 HO-CH -CH-CH -OH (B) wherein X is C 1 -6 alkoxy, NH 2 or hydrogen, or a pharmaceutically acceptable salt of either of the *e foregoing, a phosphate ester derivative of either of the 20 foregoing wherein one or both of the acyclic-OH groups are replaced by (HO) 2 groups or salts thereof or wherein the two OH groups are replaced by bridging PO(OH)-O- group and/or an acyl derivative of either of the foregoing wherein the acyl group is C2- 7 alkanoyl, S 25 C2-7 alkoxycarbonyl or benzoyl optionally substituted by one or two groups selected from C 1 -6 alkyl, C 1 -6 alkoxy or halo.

The term "acyl derivative" is used herein to include any derivative of the compounds of formula in which one or more acyl groups are present. Such derivatives are included as pro-drugs of the compounds of formula in addition to those derivatives which are per se biologically active.

Examples of pro-drugs, pharmaceutically acceptable salts and derivatives are as described in the aforementioned .9 920629,dblet.27,50600.res,3 ur ,I

L

1 3a European Patent references, the subject matter of which are incorporated herein by reference.

A particular pro-drug of interest is 9-(4-acetoxy-3acetoxymethylbut-1-yl)-2-aminopurine, known as famciclovir.

The compound of formula may also be in one of the forms disclosed in EP-A-216459 (Beecham Group The compound of formula pro-drugs, salts and derivative may be prepared as described in the e e *o l o •o oo oeel• 920629dbieL27,50600.res,4 Ua re 4 B2692 02 03 04 06 07 08 09 11 12 1 1 5 19 21 24 26 27 29 31 32 33 34 36 37 aforementioned European Patent references.

The compound may be administered by the oral route to humans and may be compounded in the form of syrup, tablets or capsule. When in the form of a tablet, any pharmaceutical carrier suitable for formulating such solid compositions may be used, for example magnesium stearate, starch, lactose, glucose, rice, flour and chalk. The compound may also be in the form of an ingestible capsule, for example of gelatin, to contain the compound, or in the form of a syrup, a solution or a suspension. Suitable liquid pharmaceutical carriers include ethyl alcohol, glycerine, saline and water to which flavouring or colouiring agents may be added to form syrups.

For parenteral administration, fluid unit dose forms are prepared containing the compound and a sterile vehicle. The compound depending on the vehicle and the concentration, can be either suspended or dissolved.

Parenteral solutions are normally prepared by dissolving the compound in a vehicle and filter sterilising before filling into a suitable vial or ampoule and sealing. Advantageously, adjuvants such as a local anaesthetic, preservatives and buffering agents are also dissolved in the vehicle. To enhance the stability, the composition can be frozen after filling into the vial and the water removed under vacuum.

Parenteral suspensions are prepared in substantially the same manner except that the compound is suspended in the vehicle instead of being dissolved and sterilised by exposure to ethylene oxide before suspending in the sterile vehicle. Advantageously, a surfactant or wetting agent is included in the 01 5 B2692 02 03 composition to facilitate uniform distribution of the 04 compound of the invention.

06 Preferred parenteral formulations include aqueous 07 formulations using sterile water or normal saline, at a 08 pH of around 7.4 or greater.

09 As is common practice, the compositions will usually be 11 accompanied by written or printed directions for use in 12 the medical treatment concerned.

14". An amount effective to treat a hepatitis B virus I. infection depends on the nature and severity of the infection and the weight of the mammal.

0* 0' A suitable dosage unit might contain from 50mg to ig of 19 active ingredient, for example 100 to 500mg. Such doses may be administered 1 to 4 times a day or more 21 usually 2 or 3 times a day. The effective dose of compound will, in general, be in the range of from 0.2 23.' to 40mg per kilogram of body weight per day or, more 24 usually, 10 to 20 mg/kg per day.

26 The present invention also provides the use of a 27 compound of formula or a pro-drug, or a pharmaceutically acceptable salt, phosphate ester 29 and/or acyl derivative of either of the foregoing, in the preparation of a medicament for use in, the 31 treatment of hepatitis B virus infections in mammals, 32 including humans. Such treatment may be carried out in 33 the manner as hereinbefore described.

34 The present invention further provides a pharmaceutical 36 composition for use in the treatment of hepatitis B 37 virus infections, which comprises an effective amount .01 6 B2692 02 03 of a compound of formula or a pro-drug, or a 04 pharmaceutically acceptable salt, phosphate ester and/or acyl derivative of either of the foregoing, and 06 a pharmaceutically acceptable carrier. Such 07 compositions may be prepared in the manner as 08 hereinafter described.

09 The activity of the compounds of formula and 11 pro-drugs, salts, phosphate ester and/or acyl 12 derivatives against hepatitis B virus., may be identified according to the following Test Protocol.

Test for Activity against Hepatitis B virus in ducks 1909 17"" Penciclovir and famciclovir were each tested at two 2: dose levels against hepatitis B virus in ducks.

19 Administration was by oral gavage to two ducks at each dose level.

21 22." Dosage was twice daily Monday to Friday inclusive; once daily Saturday and Sunday, continuing for 3 weeks.

24 The compounds showed activity against duck hepatitis B 26 virus in the above test. Activity was demonstrated by 27 a large reduction in the plasma concentration of duck hepatitis virus DNA and DNA polymerase during 29 treatment. The Table shows the blood levels of administered drug.

cc. a a cc C a c a a a cc a cc. cc ccc *cc cc 0 cc C cc* c cc cc c cc a c a c ecCac eec c cc ccc. cc a C C a

TABLE

Blood levels of Denciclovir in Pekin ducks after oral dosina with penciclovir or famciclovir Compound Dose Penciclovir concentration (jiM) in blood at (min) AUC administered (mg/kg) Duck No. 15 30 60 120 240 360 (1JM hr) penciclovirl 100 142 43 44 40 18 3.6 1.1 92 163 42 38 443 21 2.7 -0.5 139 24 28 183 12 2.8 -0.5 169 41 30 193 10 2.6 ND4 57 famciclovirl 25 ill 22 31 34 33 14 6.1 126 153 18 202 25 20 4.4 -0.5 117 8.7 8.42 7.5 2.0 0.5 N.D.

4 154 5.1 3.92 3.5 2.0 1.4 1.0 12 Notes 1. Penciclovir administered as a suspension in 1% carboxymethyl cellulose in water containix.g 1% tween 80. Famciclovir administered as a solution in water.

2. Samples collected at 32 min.

3. Samples collected at 65 min.

4. N.S. =not detected; limit of assay 0.5 ]JM.

AUC Area under the 0-6 hr. concentration/time curve.

Claims

1. A method of treatment of hepatitis B virus infections in mammals which method comprises the administration to the mammal in need of such treatment, an effective amount of a compound of formula 0 N NH 2 (CH 2 2 2 (A) HO-CH -CH-CH OH or a pro-drug of the compound of formula of formula 2 2 i y I 20 HO-CH -CH-CH2-OH (B) wherein X is C_-6 alkoxy, NH 2 or hydrogen, or a pharmaceutically acceptable salt of either of the foregoing, a phosphate ester derivative of either of the foregoing wherein one or both of the acyclic-OH groups are replaced by (HO) 2 groups or salts thereof or wherein the two OH groups are replaced by bridging PO(OH)-O- group and/or an acyl derivative of either of the foregoing wherein the acyl group is C2- 7 alkanoyl, C 2 7 alkoxycarbonyl or benzoyl optionally substituted by one or two groups selected from C 1 -6 alkyl, C 1 6 alkoxy or halo.

2. A method according to claim 1 wherein the compound administered is penciclovir, of formula

3. A method according to claim 1 wherein the compound administered is the sodium salt hydrate of the compound S 920629,dbletl27,50600.res,8 -9- of formla

4. A method according to claim 3 wherein the compound is administered parenterally in an aqueous formulation.

A method according to claim 1 wherein the pro-drug compound of formula is famciclovir, wherein X is hydrogen and wherein the two OH groups are in the form of the acetyl derivative. r r

6. A method according to claim 5 wherein is administered orally.

7. A method according to claim 1 wherein administered is in a 50mg to Ig unit dose. the compound the compound DATED this 29th day of June, 1992 Beecham Group p.l.c. By Its Patent Attorneys DAVIES COLLISON CAVE 92629,dblet.127,50600.rcs,9 -j